Claude Code Example

Access Claude via the claude-cli npm package in OpenSandbox.

Start OpenSandbox server [local]

Pre-pull the code-interpreter image (includes Node.js):

docker pull sandbox-registry.cn-zhangjiakou.cr.aliyuncs.com/opensandbox/code-interpreter:v1.1.0

# use docker hub
# docker pull opensandbox/code-interpreter:v1.1.0

Then start the local OpenSandbox server, stdout logs will be visible in the terminal:

uv pip install opensandbox-server
opensandbox-server init-config ~/.sandbox.toml --example docker
opensandbox-server

Create and Access the Claude Sandbox

# Install OpenSandbox package
uv pip install opensandbox

# Run the example (requires SANDBOX_DOMAIN / SANDBOX_API_KEY / ANTHROPIC_AUTH_TOKEN)
uv run python examples/claude-code/main.py

The script installs the Claude CLI (npm i -g @anthropic-ai/claude-code@latest) at runtime (Node.js is already in the code-interpreter image), then sends a simple request claude "Compute 1+1=?.". Auth is passed via ANTHROPIC_AUTH_TOKEN, and you can override endpoint/model with ANTHROPIC_BASE_URL / ANTHROPIC_MODEL.

Headless Mode and Session Resume

The example script also runs the two patterns used by coding-agent integrations: a headless run with structured output, and a follow-up turn that resumes the same conversation.

Turn 1: headless run with structured output

claude -p "Remember this for later: my favorite sandbox number is 42." --output-format json

With -p (print mode) the CLI answers the prompt and exits. --output-format json prints the reply, session_id, usage, and cost metadata as a single JSON object, so the script extracts session_id for the next turn.

Turn 2: resume the session

claude -p "What is my favorite sandbox number? Reply with just the number." \
  --resume <session_id> --output-format json

--resume continues a specific conversation with its context intact — the reply recalls "42" from turn 1. --continue resumes the most recent conversation instead; an explicit --resume <session_id> stays deterministic when several conversations live in the same sandbox.

Concurrent follow-ups

Add --fork-session to --resume / --continue to create a new session ID instead of reusing the original, so parallel follow-ups on the same conversation don't overwrite each other.

Permission prompts in unattended runs

There is no terminal to answer permission prompts in a -p run: requests that would prompt are denied, so a task that needs a tool (file edits, shell commands) can fail. Two common remedies for agent workloads:

• --dangerously-skip-permissions (equivalent to --permission-mode bypassPermissions) runs tools without prompts — a common choice inside an ephemeral OpenSandbox container, where the sandbox itself is the isolation boundary.
• --permission-mode dontAsk stays fail-closed: only tools pre-approved by your permission rules run — the standard pattern for locked-down CI. (--permission-prompts none, Claude Code v2.1.259+, is the print-mode equivalent.)

The interactive UI needs a TTY

The interactive REPL (claude "...") renders its UI, including permission prompts, on a terminal. Through a plain command pipe there is no way to answer a prompt, so the run can wait indefinitely. Use -p for scripted runs, or drive the interactive UI over a PTY session.

To receive output as it is generated (token-level events) instead of a single final JSON object, use --output-format stream-json --verbose --include-partial-messages.

Environment Variables

Variable	Default	Description
SANDBOX_DOMAIN	localhost:8080	Sandbox service address
SANDBOX_API_KEY	(optional for local)	API key if your server requires authentication
SANDBOX_IMAGE	sandbox-registry.cn-zhangjiakou.cr.aliyuncs.com/opensandbox/code-interpreter:v1.1.0	Sandbox image to use
ANTHROPIC_AUTH_TOKEN	(required)	Your Anthropic auth token
ANTHROPIC_BASE_URL	(optional)	Anthropic API endpoint (e.g., self-hosted proxy)
ANTHROPIC_MODEL	claude_sonnet4	Model name

References

• claude-code - NPM package for Claude Code CLI
• Claude Code headless mode - Print mode, output formats, and session resume
• Source code on GitHub